Generally, a building has a window system for both lighting and ventilating purposes. The window system includes a window sash which is directly installed at the building, and a window which is coupled to the window sash in a hinged or sliding manner. The window includes a frame which is coupled to the window sash, and a glass plate which is fixed to the frame.
Typically, a decoration sheet with high weather resistance is attached to outer surfaces of the window sash and frame which are exposed outside the building. Because the decoration sheet functions to protect the window sash and frame from the external environment such as ultraviolet ray and moisture, it has high weather resistance against the ultraviolet ray, moisture and the like.
Meanwhile, in order to provide an esthetic appearance of the window sash and frame, the decoration sheet having an effect of metallic feeling is recently required by the market. For this end, there have been provided a decoration sheet in which hair line is formed on a PVC sheet and a decoration sheet in which hair line is formed on a PET sheet. In case of the former, there are limitations in providing the effect of metallic feeling, and in case of latter, the weather resistance of PET is too low, and thus it is improper as the decoration sheet with the weather resistance.
In Japanese Patent Laid-Open No. 2004-142439, there is disclosed a metallic luster sheet having metallic feeling as well as weather resistance. The metallic luster sheet includes a base sheet which is contacted with an object, a fine unevenness layer stacked on an upper surface of the base sheet, and a protecting sheet stacked on an upper surface of the fine unevenness layer. The base sheet is formed of acryl, PVC, PET and so on, the metallic luster sheet is formed of aluminum, nickel, chrome and the like, the fine unevenness layer is formed of acryl, PVC and the like, and the protecting sheet is formed of acryl and the like.
The metallic luster sheet includes a metallic luster layer formed of a metallic material, and the hair line is formed at the metallic luster layer so as to provide the effect of metallic feeling. Further, the base sheet and the protecting sheet are provided on both upper and lower surfaces of the metallic luster layer so as to provide the high weather resistance.
However, in the metallic luster sheet as described above, the hair line is formed on the metallic luster layer formed of aluminum, nickel, chrome and the like through the fine unevenness layer. Therefore, in the metallic luster sheet, there is a problem in that the fine unevenness layer has to be necessarily provided between the metallic luster layer and the protecting layer.
Furthermore, in the metallic luster sheet as described above, since the metallic luster layer formed of the metallic material is contacted with the fine unevenness layer and base sheet which are formed of a polymer resin, there is another problem in that adhesive strength between the metallic luster layer and the fine unevenness layer and between the metallic luster layer and the base sheet is not ensured sufficiently.